Pub Date : 2014-07-31DOI: 10.1142/S1793617914500038
M. R. Jalal, M. Pishdast, A. E. Majd
In this paper, the evolution of shot-noise micro-bunching in a SASE-FEL is investigated. First, a simple one-dimensional model for phase-space evolution of electrons is presented. Then, for an e-beam with random distribution of electrons (i.e. with shot-noise), the start-up and growth of micro-bunching is calculated. It is shown that shot-noise micro-bunching starts in random positions within the e-beam and grows in amplitude and extent. The final micro-bunching pattern contains distinct regions each with a coherent micro-bunching but with no phase relation with that of the others. Such distinct micro-bunched regions show themselves in the so-called spiky pattern of output radiation.
{"title":"Shot-noise triggered electron beam micro-bunching in SASE-FELs","authors":"M. R. Jalal, M. Pishdast, A. E. Majd","doi":"10.1142/S1793617914500038","DOIUrl":"https://doi.org/10.1142/S1793617914500038","url":null,"abstract":"In this paper, the evolution of shot-noise micro-bunching in a SASE-FEL is investigated. First, a simple one-dimensional model for phase-space evolution of electrons is presented. Then, for an e-beam with random distribution of electrons (i.e. with shot-noise), the start-up and growth of micro-bunching is calculated. It is shown that shot-noise micro-bunching starts in random positions within the e-beam and grows in amplitude and extent. The final micro-bunching pattern contains distinct regions each with a coherent micro-bunching but with no phase relation with that of the others. Such distinct micro-bunched regions show themselves in the so-called spiky pattern of output radiation.","PeriodicalId":166807,"journal":{"name":"Advances in Synchrotron Radiation","volume":"107 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114827098","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-07-31DOI: 10.1142/S1793617914500014
G. Sharma, M. Gehlot, G. Mishra
Bi-harmonic undulators are designed and field integrals are measured in a pulsed wire bench. An analytical formula is given for the shim counting and positioning along the length of the undulator. It is observed that the wire rigidity and stiffness of the thick wire do not affect the bi-harmonic undulator field measurement and gives comparable results with hall probe data.
{"title":"Pulsed wire measurements of harmonic undulators for free electron laser","authors":"G. Sharma, M. Gehlot, G. Mishra","doi":"10.1142/S1793617914500014","DOIUrl":"https://doi.org/10.1142/S1793617914500014","url":null,"abstract":"Bi-harmonic undulators are designed and field integrals are measured in a pulsed wire bench. An analytical formula is given for the shim counting and positioning along the length of the undulator. It is observed that the wire rigidity and stiffness of the thick wire do not affect the bi-harmonic undulator field measurement and gives comparable results with hall probe data.","PeriodicalId":166807,"journal":{"name":"Advances in Synchrotron Radiation","volume":"184 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131467391","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-07-31DOI: 10.1142/S1793617914500026
M. R. Jalal, F. Aghamir
Evolution of bunching factor in different sections of an electron beam moving along an undulator is investigated. An averaging code is developed to calculate the average value of bunching in two different modes. In the first mode, the magnitude of bunching factor is averaged. In the second mode, the average of bunching factor is calculated taking into account its complex nature. The first averaging shows that all sections have similar trend of evolution; but, the result is completely different for the second averaging. The difference is attributed to the inherent phase cancellation present in the second mode of averaging.
{"title":"Bunching evolution within the electron beam of a SASE FEL","authors":"M. R. Jalal, F. Aghamir","doi":"10.1142/S1793617914500026","DOIUrl":"https://doi.org/10.1142/S1793617914500026","url":null,"abstract":"Evolution of bunching factor in different sections of an electron beam moving along an undulator is investigated. An averaging code is developed to calculate the average value of bunching in two different modes. In the first mode, the magnitude of bunching factor is averaged. In the second mode, the average of bunching factor is calculated taking into account its complex nature. The first averaging shows that all sections have similar trend of evolution; but, the result is completely different for the second averaging. The difference is attributed to the inherent phase cancellation present in the second mode of averaging.","PeriodicalId":166807,"journal":{"name":"Advances in Synchrotron Radiation","volume":"487 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122750180","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-07-31DOI: 10.1142/S179361791450004X
J. Mazher, Shabina Khan, Pankaja Singh
Beryllium doping has been used to harden the inherently soft zinc-selenides semiconductor mixed alloys. Stoichiometric semiconductor ternary alloys of BexZn1-xSe have been synthesized by the Bridgeman technique. Extended X-ray absorption fine structure (EXAFS) spectroscopy — in a state-of-art synchrotron-based method — is performed by varying the dopant Be concentration of Be from 6% to 55% in the zinc–selenide host semiconductor. EXAFS analyses is carried out to study the next neighbor and next nearest neighbor atomic positions, nature of the substitutional doping, extent of bond length homogeneity, presence of involuntary contrast among the path distances, and the cross over from soft to hard character of the ternary on increasing Be concentration. Our results indicate the presence of an impulsive nature of hardening in the ternary with a disparity at the lower and the higher doping levels. The observation of impulsive hardening of the substitutional dopants in the semiconductor lattice is explained by the help of self-accommodative attributes of the host lattice.
{"title":"EXAFS studies of novel impulsive hardening in the Be–Zn–Se semiconductor alloys","authors":"J. Mazher, Shabina Khan, Pankaja Singh","doi":"10.1142/S179361791450004X","DOIUrl":"https://doi.org/10.1142/S179361791450004X","url":null,"abstract":"Beryllium doping has been used to harden the inherently soft zinc-selenides semiconductor mixed alloys. Stoichiometric semiconductor ternary alloys of BexZn1-xSe have been synthesized by the Bridgeman technique. Extended X-ray absorption fine structure (EXAFS) spectroscopy — in a state-of-art synchrotron-based method — is performed by varying the dopant Be concentration of Be from 6% to 55% in the zinc–selenide host semiconductor. EXAFS analyses is carried out to study the next neighbor and next nearest neighbor atomic positions, nature of the substitutional doping, extent of bond length homogeneity, presence of involuntary contrast among the path distances, and the cross over from soft to hard character of the ternary on increasing Be concentration. Our results indicate the presence of an impulsive nature of hardening in the ternary with a disparity at the lower and the higher doping levels. The observation of impulsive hardening of the substitutional dopants in the semiconductor lattice is explained by the help of self-accommodative attributes of the host lattice.","PeriodicalId":166807,"journal":{"name":"Advances in Synchrotron Radiation","volume":"06 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127269774","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-06-01DOI: 10.1142/S1793617911000305
T. Kühn, S. Zinoveva, J. Hormes, T. Vitova, R. Louis, P. Datta, J. Göttert, C. Kumar
X-ray absorption spectroscopy (XAS) is an extremely valuable tool for the characterization of the electronic and geometric properties of nanoparticles. However, there are drawbacks when it comes, for example, to time-resolved in situ measurements of wet-chemical synthetic reactions or when X-ray absorption near edge structure (XANES) spectra are used for characterizing atoms that occupy different sites in a nanoparticle. In this paper, we report results of test experiments using resonant inelastic X-ray scattering (RIXS) for obtaining high-resolution spectra that allow in principle site- and/or valency-specific XANES measurements. For a detailed analysis of wet-chemical reactions, a microreactor system is used in which time resolution is obtained by spatial resolution, i.e., by measuring spectra at various points along the microreactor. This system provides significantly better resolution (in the order of milliseconds) compared to conventional techniques.
{"title":"CHARACTERIZING METALLIC NANOPARTICLES BY X-RAY ABSORPTION SPECTROSCOPY: TWO NEW APPROACHES","authors":"T. Kühn, S. Zinoveva, J. Hormes, T. Vitova, R. Louis, P. Datta, J. Göttert, C. Kumar","doi":"10.1142/S1793617911000305","DOIUrl":"https://doi.org/10.1142/S1793617911000305","url":null,"abstract":"X-ray absorption spectroscopy (XAS) is an extremely valuable tool for the characterization of the electronic and geometric properties of nanoparticles. However, there are drawbacks when it comes, for example, to time-resolved in situ measurements of wet-chemical synthetic reactions or when X-ray absorption near edge structure (XANES) spectra are used for characterizing atoms that occupy different sites in a nanoparticle. In this paper, we report results of test experiments using resonant inelastic X-ray scattering (RIXS) for obtaining high-resolution spectra that allow in principle site- and/or valency-specific XANES measurements. For a detailed analysis of wet-chemical reactions, a microreactor system is used in which time resolution is obtained by spatial resolution, i.e., by measuring spectra at various points along the microreactor. This system provides significantly better resolution (in the order of milliseconds) compared to conventional techniques.","PeriodicalId":166807,"journal":{"name":"Advances in Synchrotron Radiation","volume":"302 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117055113","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2008-12-01DOI: 10.1142/S1793617908000173
R. Hussain, N. Krumpa, J. Strachan, D. Clarke, U. Wagner, B. Macdonald, D. Reading, T. Cobb, I. Gillingham, A. Price, M. Smith, G. Siligardi
Synchrotron circular dichroism (CD) is already a valuable technique for studies of protein folding, conformational changes and enzyme mechanisms, as well as secondary structure determination. Exciting new potential applications exist in protein folding, protein complex formation for Proteomics, and ligand/drug screening for Functional Genomics. With the 3 GeV synchrotron of Diamond Light Source we can collimate a very small size light beam (about 2 mm (H) × 1 mm (V)) with high photon flux (estimated 8 × 1013 (ph/s/0.1%bw) at 6 eV and 300 mA). The small beam size will enable the measurement of smaller sample volumes that previously has not been possible.
同步加速器圆二色性(CD)已经成为研究蛋白质折叠、构象变化和酶机制以及二级结构测定的一种有价值的技术。令人兴奋的新的潜在应用存在于蛋白质折叠，蛋白质组学的蛋白质复合物形成和功能基因组学的配体/药物筛选。利用金刚石光源的3 GeV同步加速器，我们可以准直一个非常小的光束(约2 mm (H) × 1 mm (V))，具有高光子通量(估计为8 × 1013 (ph/s/0.1%bw)，在6 eV和300 mA)。小光束尺寸将使以前不可能测量的更小的样本量成为可能。
{"title":"DESIGN OF B23 CIRCULAR DICHROISM BEAMLINE AT DIAMOND LIGHT SOURCE","authors":"R. Hussain, N. Krumpa, J. Strachan, D. Clarke, U. Wagner, B. Macdonald, D. Reading, T. Cobb, I. Gillingham, A. Price, M. Smith, G. Siligardi","doi":"10.1142/S1793617908000173","DOIUrl":"https://doi.org/10.1142/S1793617908000173","url":null,"abstract":"Synchrotron circular dichroism (CD) is already a valuable technique for studies of protein folding, conformational changes and enzyme mechanisms, as well as secondary structure determination. Exciting new potential applications exist in protein folding, protein complex formation for Proteomics, and ligand/drug screening for Functional Genomics. With the 3 GeV synchrotron of Diamond Light Source we can collimate a very small size light beam (about 2 mm (H) × 1 mm (V)) with high photon flux (estimated 8 × 1013 (ph/s/0.1%bw) at 6 eV and 300 mA). The small beam size will enable the measurement of smaller sample volumes that previously has not been possible.","PeriodicalId":166807,"journal":{"name":"Advances in Synchrotron Radiation","volume":"186 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116976302","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2008-12-01DOI: 10.1142/S1793617908000240
G. Greaves, M. Wilding, S. Fearn, D. Langstaff, F. Kargl, Q. V. Van, L. Hennet, I. Pozdnyakova, O. Majérus, R. Cernik, Christopher M. Martin
Modern levitation furnaces are enabling melting and freezing of refractory materials like Al2O3 to be studied in depth with synchrotron radiation techniques. Whilst α-Al2O3 is a close packed Debye-like solid, liquid Al2O3 has smaller coordination numbers and the structure has network-like characteristics. Under contactless conditions, substantial under cooling can be achieved. Melting involves a significant decrease in density which is approximately recovered on recrystallization, both of which can be followed with high speed video imaging. Freezing occurs with a burst of energy — recalescence — which substantially raises the temperature momentarily. Using Rietveld refinement the density of α-Al2O3 and the mean square displacement of the average atom 〈μ2〉 can be followed up to the melting point and upon freezing using in situ X-ray diffraction. As melting is approached 〈μ2〉 for α-Al2O3 exceeds the harmonic approximation of the Lindemann–Galvarry law and for liquid Al2O3 above the melting point 〈μ2〉 appear...
{"title":"IN SITU STRUCTURAL STUDIES OF ALUMINA DURING MELTING AND FREEZING","authors":"G. Greaves, M. Wilding, S. Fearn, D. Langstaff, F. Kargl, Q. V. Van, L. Hennet, I. Pozdnyakova, O. Majérus, R. Cernik, Christopher M. Martin","doi":"10.1142/S1793617908000240","DOIUrl":"https://doi.org/10.1142/S1793617908000240","url":null,"abstract":"Modern levitation furnaces are enabling melting and freezing of refractory materials like Al2O3 to be studied in depth with synchrotron radiation techniques. Whilst α-Al2O3 is a close packed Debye-like solid, liquid Al2O3 has smaller coordination numbers and the structure has network-like characteristics. Under contactless conditions, substantial under cooling can be achieved. Melting involves a significant decrease in density which is approximately recovered on recrystallization, both of which can be followed with high speed video imaging. Freezing occurs with a burst of energy — recalescence — which substantially raises the temperature momentarily. Using Rietveld refinement the density of α-Al2O3 and the mean square displacement of the average atom 〈μ2〉 can be followed up to the melting point and upon freezing using in situ X-ray diffraction. As melting is approached 〈μ2〉 for α-Al2O3 exceeds the harmonic approximation of the Lindemann–Galvarry law and for liquid Al2O3 above the melting point 〈μ2〉 appear...","PeriodicalId":166807,"journal":{"name":"Advances in Synchrotron Radiation","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117003794","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2008-12-01DOI: 10.1142/S179361790800015X
T. Nomoto, S. Yagi, K. Soda, H. Namatame, M. Taniguchi
The adsorption reaction of (CH3)2S on oxygen pre-covered Rh(111) surface has been investigated by XPS and S K-edge NEXAFS techniques. The dissociation of (CH3)2S to methanethiolate and atomic sulfur occurs without regard to the coverage of pre-covered oxygen at 90 K. XPS and NEXAFS results indicate that some of the adsorbates bond to atomic oxygen via their sulfur atom. It seems that adsorbates bonding to atomic oxygen are difficult to desorb from the surface, even if it is heated up to 200 K.
{"title":"THERMALLY DEPENDENT ADSORPTION OF (CH3)2S ON OXYGEN PRE-COVERED Rh SURFACE STUDIED BY XPS AND NEXAFS","authors":"T. Nomoto, S. Yagi, K. Soda, H. Namatame, M. Taniguchi","doi":"10.1142/S179361790800015X","DOIUrl":"https://doi.org/10.1142/S179361790800015X","url":null,"abstract":"The adsorption reaction of (CH3)2S on oxygen pre-covered Rh(111) surface has been investigated by XPS and S K-edge NEXAFS techniques. The dissociation of (CH3)2S to methanethiolate and atomic sulfur occurs without regard to the coverage of pre-covered oxygen at 90 K. XPS and NEXAFS results indicate that some of the adsorbates bond to atomic oxygen via their sulfur atom. It seems that adsorbates bonding to atomic oxygen are difficult to desorb from the surface, even if it is heated up to 200 K.","PeriodicalId":166807,"journal":{"name":"Advances in Synchrotron Radiation","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133102231","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2008-12-01DOI: 10.1142/S1793617908000264
K. Miura, M. Morihara, T. Nomoto, S. Yagi, K. Soda, G. Kutluk, H. Namatame, M. Taniguchi
The Pd nanoparticles were fabricated by the gas evaporation method without any capping molecules. It is found that the average diameter of the nanoparticles are 1.7 nm with standard deviation of 0.8 nm by AFM observations. The chemical states of the nanoparticles were measured by the in situ XPS. The XPS results indicate that the chemical states of the nanoparticles become almost the same as the bulk Pd. The chemical states of the air-exposed Pd nanoparticles were also observed by the ex situ XPS and NEXAFS methods. Both ex situ XPS and NEXAFS measurements indicate that the nanoparticles were naturally oxidized under an atmospheric environment. Considering from the behavior of Pd 3d XPS and the diameter of nanoparticles, it is suggested that the depth of oxidized Pd layer is less than 1.4 monolayer from the nanoparticles surface.
{"title":"IN SITU XPS STUDY OF Pd NANOPARTICLE FABRICATED BY GAS EVAPORATION METHOD","authors":"K. Miura, M. Morihara, T. Nomoto, S. Yagi, K. Soda, G. Kutluk, H. Namatame, M. Taniguchi","doi":"10.1142/S1793617908000264","DOIUrl":"https://doi.org/10.1142/S1793617908000264","url":null,"abstract":"The Pd nanoparticles were fabricated by the gas evaporation method without any capping molecules. It is found that the average diameter of the nanoparticles are 1.7 nm with standard deviation of 0.8 nm by AFM observations. The chemical states of the nanoparticles were measured by the in situ XPS. The XPS results indicate that the chemical states of the nanoparticles become almost the same as the bulk Pd. The chemical states of the air-exposed Pd nanoparticles were also observed by the ex situ XPS and NEXAFS methods. Both ex situ XPS and NEXAFS measurements indicate that the nanoparticles were naturally oxidized under an atmospheric environment. Considering from the behavior of Pd 3d XPS and the diameter of nanoparticles, it is suggested that the depth of oxidized Pd layer is less than 1.4 monolayer from the nanoparticles surface.","PeriodicalId":166807,"journal":{"name":"Advances in Synchrotron Radiation","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131692110","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2008-12-01DOI: 10.1142/S1793617908000197
K. Tabayashi, T. Yamanaka, H. Namatame, M. Taniguchi
Inner-shell excitation spectra and fragmentation of nitromethane (NM) clusters have been studied in the oxygen K-edge region under cluster beam conditions. Besides the protonated clusters (NM)n · H+, we identified the production of series of mixed fragment-cluster cations, [(NM)n · X+, (X = CH3, NO, NO2)] in time-of-flight spectra of the NM clusters. "Cluster-specific" excitation spectra could be generated without contribution of free molecules by monitoring partial-ion-yield spectra of the fragments originating from the clusters. Comparison of the "cluster-specific" band with "monomer" band revealed that the first resonance ${rm O}1s to pi^*_{rm NO}$ band of clusters shifts to a high energy by ~ 0.1 eV. The core-excitation spectrum to the antibonding state compared well with theoretical prediction. The band-shift of the first ${rm O}1s to pi ^*_{rm NO}$ was interpreted as being due to the weak hydrogen-bond interaction formed upon clustering. Fragmentation mechanism of the core-excited NM cluster...
{"title":"INNER-SHELL EXCITATION AND FRAGMENTATION OF NITROMETHANE CLUSTERS AT THE OXYGEN K-EDGE","authors":"K. Tabayashi, T. Yamanaka, H. Namatame, M. Taniguchi","doi":"10.1142/S1793617908000197","DOIUrl":"https://doi.org/10.1142/S1793617908000197","url":null,"abstract":"Inner-shell excitation spectra and fragmentation of nitromethane (NM) clusters have been studied in the oxygen K-edge region under cluster beam conditions. Besides the protonated clusters (NM)n · H+, we identified the production of series of mixed fragment-cluster cations, [(NM)n · X+, (X = CH3, NO, NO2)] in time-of-flight spectra of the NM clusters. \"Cluster-specific\" excitation spectra could be generated without contribution of free molecules by monitoring partial-ion-yield spectra of the fragments originating from the clusters. Comparison of the \"cluster-specific\" band with \"monomer\" band revealed that the first resonance ${rm O}1s to pi^*_{rm NO}$ band of clusters shifts to a high energy by ~ 0.1 eV. The core-excitation spectrum to the antibonding state compared well with theoretical prediction. The band-shift of the first ${rm O}1s to pi ^*_{rm NO}$ was interpreted as being due to the weak hydrogen-bond interaction formed upon clustering. Fragmentation mechanism of the core-excited NM cluster...","PeriodicalId":166807,"journal":{"name":"Advances in Synchrotron Radiation","volume":"80 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133611171","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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